Officers are continuing a lengthy inquiry into allegations made by a woman, who was 50 years old at the time, that she was raped in her home on Westlea in Clowne.
The offence happened sometime between 1.45am and 2.10am on Thursday, August 26 2010 and despite extensive enquiries by Derbyshire officers the offender has not been traced.
Detective sergeant Ryan Finnegan said: “We have forensic evidence which we hope will help us build a case against the offender or eliminate any innocent suspects.
“During the past few years we have carried out DNA screening of local men but have so far not succeeded in identifying a suspect.
“It’s vitally important that we try everything we can to get justice for the victim in this case. If anyone has any information that would lead us to the offender they can contact me by ringing 101 or pass information anonymously by calling Crimestoppers on 0800 555 111.”